Client can make an off-chain deal to miner. The miner will use existing or new CC sector to storage client's real data. If client want its off-chain data on chain, miner should upgrade the CC sectors to Regular Sectors with resealing.
Right now, the total network power is more than 6EiB，but the real storage is just only 15PB（https://storage.filecoin.io/). There are a lot of CC sectors with the zero deal. The miner should have an easy way to use the existing CC sectors to store the real data from the clients, no more resealing. So that it can solve the problem about the idle hardware equipment.
The currently method is that the pledged sector can be replaced with a new sector containing deals.(https://docs.filecoin.io/mine/lotus/sector-pledging/#upgrading-pledged-sectors). However, it requires the deal to publish and new sector to seal. It will take up more resources of the miners and also occupy more resources of the network. Client storage costs will also increase because of it.
The client can choose whether to publish its own data and deal on chain or not.
Storing the off-chain data will save the gas fee, which is so expensive when the base fee is high especially. Like Verified data, the miners can provide the client another lower storage price than on-chain mode. The clients also can download files from the miner by the file CID.
If the client needs, it can change its off-chain deal on chain. The miner will migrate the data into the regular sector.
Especially, when the client finds that the miner do not provide services any more, it can create an arbitration or appeal. If the miner lost the data, the miner needs to pay the customer compensation for the loss of data. Meanwhile, the power and pledge will also be slashed. (Perhaps we can discuss another FIP in detail)
EDIT: I misinterpret "no more resealing" as no sealing at all and then got too excited about prospects. The ideas below are incorrect, so feel free to ignore them.
Another cool side of the proposal - is that the described unsealed/off-chain data can be regular IPLD formatted data and thus retrievable from IPFS. This could be an additional solution for Filecoin/IPFS interoperability issue and even implement remote pinning API for miners. For a variety of cases, off-chain deals would give enough guarantees about data being stored.
Also, it looks similar to optimistic rollup schema, but in this case, this can be called an 'optimistic storage deal'. That is, the deal is optimistically stored off-chain as IPLD data in the CC sector, which can be (1) upgraded to an on-chain deal and (2) disputed in the case it's not stored anymore(verification procedure?).